ICELAND’s Volcanic EMISSIONs Analysis & LOS ANGELES Eruptions!

Dear Readers: I wanted to spend a little time delving into my love of science and history by providing some updates about the eruption in Iceland — as well as a nod to my interest in current events by noting an interesting civil eruption that happened in Los Angeles.

Co/AP; Marco Fulle, not for commercial use

One of the points of curiosity I had was what types of gasses were being emitted, and in what volume. As I noted in a previous post, the 1783 Laki Fissure eruptions created fumes rich in water vapor, sulfur oxides, and fluorine. This combination poisoned to death about 20% of Iceland’s population, impacted the respiratory health of millions of Europeans, and cooled the global climate to such an extent there was several years of severe crop failures throughout Europe. This via Wikipedia.

An estimated 120 million tons of sulfur dioxide were emitted, approximately equivalent to three times the total annual European industrial output in 2006, and also equivalent to a Mount Pinatubo-1991 eruption every three days.[6] This outpouring of sulfur dioxide during unusual weather conditions caused a thick haze to spread across western Europe, resulting in many thousands of deaths throughout 1783 and the winter of 1784.

The Icelandic volcanoes are notorious for releasing tons of sulfur oxides, such as sulfur dioxide (SO2). The USGS published this analysis in: Volcanic Gases and Their Effects

The effects of SO2 on people and the environment vary widely depending on (1) the amount of gas a volcano emits into the atmosphere; (2) whether the gas is injected into the troposphere or stratosphere; and (3) the regional or global wind and weather pattern that disperses the gas. Sulfur dioxide (SO2) is a colorless gas with a pungent odor that irritates skin and the tissues and mucous membranes of the eyes, nose, and throat. Sulfur dioxide chiefly affects upper respiratory tract and bronchi. The World Health Organization recommends a concentration of no greater than 0.5 ppm over 24 hours for maximum exposure. A concentration of 6-12 ppm can cause immediate irritation of the nose and throat; 20 ppm can cause eye irritation; 10,000 ppm will irritate moist skin within minutes.

Emission rates of SO2 from an active volcano range from 10 million tonnes/day according to the style of volcanic activity and type and volume of magma involved. For example, the large explosive eruption of Mount Pinatubo on 15 June 1991 expelled 3-5 km3 of dacite magma and injected about 17 million tonnes of SO2 into the stratosphere. The sulfur aerosols resulted in a 0.5-0.6°C cooling of the Earth’s surface in the Northern Hemisphere. The sulfate aerosols also accelerated chemical reactions that, together with the increased stratospheric chlorine levels from human-made chlorofluorocarbon (CFC) pollution, destroyed ozone and led to some of the lowest ozone levels ever observed in the atmosphere.

The SO2 tends to generate sulfuric acid mist in the atmosphere, which reflects light and heat from the sun. Subsequently, severe global cooling has often been the result of large volcanic eruptions. The color of the atmosphere also changes, as noted in this post-Laki description:

…the peculiar haze, or smokey fog, that prevailed for many weeks in this island, and in every part of Europe, and even beyond its limits, was a most extraordinary appearance, unlike anything known within the memory of man. By my journal I find that I had noticed this strange occurrence from June 23 to July 20 inclusive, during which period the wind varied to every quarter without making any alteration in the air. The sun, at noon, looked as blank as a clouded moon, and shed a rust- coloured ferruginous light on the ground, and floors of rooms; but was particularly lurid and blood-coloured at rising and setting.

The 1783 eruption result in an estimated 8 million tons of hydrogen fluoride and 120 million tons of sulfur dioxide, and created the mist that is described above that eventually become known as the “Laki haze” . The release of hydrogen fluoride killed a substantial portion of Iceland’s population via fluorine poisoning, as well as approximately 80% of sheep, 50% of cattle and 50% of horses.

The eruption of Mt. Eyjafjallajokull in Iceland has had a chilling effect on air travel, but unless the eruption starts lofting far greater amounts of volcanic material higher into the atmosphere than it has to date, or continues unabated for months, the volcano with the tongue-twisting name probably will not join the ranks of famous climate-altering volcanoes, such as Mt. Tambora in Indonesia and Mt. Pinatubo in the Philippines.